# STATUS — lex phase (Builder)

## DONE

All DoD items self-certified (BUILD phase — deferred Adversary review).

## DoD Checklist

- **D1 — numbers:** PASS. Integers and floats (including `.5`, `10.`) tokenize correctly with proper Python types (int/float).
- **D2 — operators & parens:** PASS. `+ - * / ( )` all tokenize to correct kinds. `"1+2*3"` → `NUMBER PLUS NUMBER STAR NUMBER EOF`.
- **D3 — whitespace & errors:** PASS. Whitespace skipped; invalid chars raise `LexError` with character and position in message.
- **D4 — tests green:** PASS. 11 tests, 0 failures.

## Verification Commands (for Adversary cold-verify)

```bash
# From repo root — run from a fresh clone
python -m unittest -q
# Expected: Ran 11 tests in X.XXXs / OK (exit 0)

python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('3.5*(1-2)')])"
# Expected: [('NUMBER', 3.5), ('STAR', '*'), ('LPAREN', '('), ('NUMBER', 1), ('MINUS', '-'), ('NUMBER', 2), ('RPAREN', ')'), ('EOF', None)]

python -c "from calc.lexer import tokenize; tokenize('1 @ 2')"
# Expected: raises calc.lexer.LexError: unexpected character '@' at position 2
```

## Files Produced

- `calc/__init__.py` — empty package init
- `calc/lexer.py` — `Token`, `LexError`, `tokenize()`
- `calc/test_lexer.py` — 11 unittest cases covering D1–D4